Warfarin and heparin

[re8]

For a new diagnosed PE or dvt..can we start heparin or LMWH and warfarin at the same day and time or we have to start with heparin and check PTT first. If it is in therapeutic level then we can add warfarin. Again, after INR becomes 2-3 we stop heparin
Please comment this
Thanks

---

Members don't see this ad.

 

[radiodoc99]

the guidelines say use LWMH 1g/kg SC bid (IV UHF if CrCl<20, or hemodynamic instability). You start warfarin when PTT is therapeutic or in some cases after 1st dose of LMWH and overlap x 5 d with heparin with a goal INR of 2-3. If the condition is reversible or there is a time limited risk factor then 3-6m of warfarin. this rule varies sometimes.

 

[re8]

Thank you radiodoc99

 

[jdh71]

For a new diagnosed PE or dvt..can we start heparin or LMWH and warfarin at the same day and time or we have to start with heparin and check PTT first. If it is in therapeutic level then we can add warfarin. Again, after INR becomes 2-3 we stop heparin
Please comment this
Thanks

Start them at the same time. As mentioned earlier patient will need a bridging dose of heparin and/or lovenox but 2-3 days is sufficient.

 

[muscles]

Start them at the same time. As mentioned earlier patient will need a bridging dose of heparin and/or lovenox but 2-3 days is sufficient.

Agreed. Start them together.

 

[staup]

Definitely do not start them at the same time. Seriously, don't.

Warfarin depletes the activity of some anticoagulant factors such as C and S upon first doss and it can be up to after several doses until it becomes overwhelming anticoagulant.

If someone has a clot, they are procoagulant (as in not only do they have something that predisposed them to the clot, but now the clot itself makes them procoagulant) so you have to wait until they are therapeutic on heparin or whatever you are using before starting warfarin. The very reason you are asking this question is because you have seen people do it differently or seen people wait and you didn't understand why, but there is a reason why people wait.

The majority of time you can get away with starting them together, but trust me, I have seen people either get more clots or come back with an extension of their original clot after starting warfin while not anticoagulated.

For afib, with no clot anywhere, you can start warfarin whenever. It's a different scenario.

 

[jdh71]

Definitely do not start them at the same time. Seriously, don't.

Warfarin depletes the activity of some anticoagulant factors such as C and S upon first doss and it can be up to after several doses until it becomes overwhelming anticoagulant.

If someone has a clot, they are procoagulant (as in not only do they have something that predisposed them to the clot, but now the clot itself makes them procoagulant) so you have to wait until they are therapeutic on heparin or whatever you are using before starting warfarin. The very reason you are asking this question is because you have seen people do it differently or seen people wait and you didn't understand why, but there is a reason why people wait.

The majority of time you can get away with starting them together, but trust me, I have seen people either get more clots or come back with an extension of their original clot after starting warfin while not anticoagulated.

For afib, with no clot anywhere, you can start warfarin whenever. It's a different scenario.

This is a reason to bridge the therapy, not a reason to not start them together.

 

[staup]

Incorrect.

If you are starting them together, there is a period when you are giving warfarin to a person with a clot who is not anticoagulated. You wait until you have a therapeutic aPTT, then start warfarin.

 

[jdh71]

Incorrect.

If you are starting them together, there is a period when you are giving warfarin to a person with a clot who is not anticoagulated. You wait until you have a therapeutic aPTT, then start warfarin.

If they are on heparin they are anticoagulated, this actually happens to be why we give people heparin, donchanoe . . .

 

[muscles]

Definitely do not start them at the same time. Seriously, don't.

Warfarin depletes the activity of some anticoagulant factors such as C and S upon first doss and it can be up to after several doses until it becomes overwhelming anticoagulant.

If someone has a clot, they are procoagulant (as in not only do they have something that predisposed them to the clot, but now the clot itself makes them procoagulant) so you have to wait until they are therapeutic on heparin or whatever you are using before starting warfarin. The very reason you are asking this question is because you have seen people do it differently or seen people wait and you didn't understand why, but there is a reason why people wait.

The majority of time you can get away with starting them together, but trust me, I have seen people either get more clots or come back with an extension of their original clot after starting warfin while not anticoagulated.

For afib, with no clot anywhere, you can start warfarin whenever. It's a different scenario.

This illustrates the "bridge" concept. Because warfarin introduces a temporary hypercoagulable stage, you give heparin or lovenox for a short course until follow-up PT/INR confirms that you are at a therapeutic warfarin dose.

Nobody disagrees with your point that patients just started on "warfarin while not anticoagulated" may come back w/ new clot or extension or existing clot. Heparin/LMWH eliminates this risk.

Finally, your reference to A. fib doesn't really apply to this. People started giving coumadin withOUT a heparin/LMHW bridge some time ago.

 

[staup]

This illustrates the "bridge" concept. Because warfarin introduces a temporary hypercoagulable stage, you give heparin or lovenox for a short course until follow-up PT/INR confirms that you are at a therapeutic warfarin dose.

Right, but unless heparin is at a therapeutic level, there is no bridge, because heparin is not anticoagulating anything. Hence you don't start them at the same time, you wait until heparin is therapeutic and then start warfarin, be that hours or days, whenever it happens. You can probably get away with doing them at the same time, but it's a risk, and I have seen it turn out badly.

And my point about afib is that it is a different conversation, thanks for agreeing with me.

 

[Gastrapathy]

Write the orders at the same time. The lovenox is given immediately, the warfarin is given per routine (usually with evening meds). Done. Easy.

 

[staup]

Write the orders at the same time. The lovenox is given immediately, the warfarin is given per routine (usually with evening meds). Done. Easy.

This can work.

I really have no idea why people are choosing to argue this. The patient needs to be anticoagulated before you start warfarin. Just because "they are on heparin", does not mean they are anticoagulated by a long shot. I have seen patients take more than a day to become anticoagulated on heparin when following a nomogram. They need to be on heparin with a therapeutic aPTT, which is why I would be a little cautious starting them at the same time, although most times you will get away with it.

 

[muscles]

This can work.

I really have no idea why people are choosing to argue this. The patient needs to be anticoagulated before you start warfarin. Just because "they are on heparin", does not mean they are anticoagulated by a long shot. I have seen patients take more than a day to become anticoagulated on heparin when following a nomogram. They need to be on heparin with a therapeutic aPTT, which is why I would be a little cautious starting them at the same time, although most times you will get away with it.

I think everyone understands your argument, though I've never seen it take that long to become therapeutic with heparin. Realistically, if you immediately give heparin/LMWH, by the time the coumadin is given (which like gastrapathy said, is almost always given QHS), they should be therapeutic. This is also advantageous b/c you can speed up disposition if the patient is otherwise hemodynamically stable - discharge them with prescription for coumadin and a short course of lovenox; they can f/u w/ serial PT/INR as outpatient and stop lovenox once therapeutic.

 

[jdh71]

I think everyone understands your argument, though I've never seen it take that long to become therapeutic with heparin. Realistically, if you immediately give heparin/LMWH, by the time the coumadin is given (which like gastrapathy said, is almost always given QHS), they should be therapeutic. This is also advantageous b/c you can speed up disposition if the patient is otherwise hemodynamically stable - discharge them with prescription for coumadin and a short course of lovenox; they can f/u w/ serial PT/INR as outpatient and stop lovenox once therapeutic.

I don't because it's wrong.

 

[staup]

I don't because it's wrong.

Ouch! Not nice.

Anyway jdh71, you are not in the right, ask any hematologist.

I do think most understand the argument, but for some reason they keep fighting it. I guess it's just pride eating away at them.

Muscles, you are completely right, and most times that always works. My only small point is that I have definitely seen people started on a heparin protocol, with no one paying attention to it, and a day later they still weren't therapuetic. It can happen, and there is a small chance it could be disatrous.

If you're giving the warfarin before the heparin is therapeutic, what's the reason of having a bridge? It's meaningless then because without a therapuetic aPTT, the heparin is not doing much.

Anyway, this is stupid now, I'm out.

 

[jdh71]

Ouch! Not nice.

Anyway jdh71, you are not in the right, ask any hematologist.

I do think most understand the argument, but for some reason they keep fighting it. I guess it's just pride eating away at them.

Muscles, you are completely right, and most times that always works. My only small point is that I have definitely seen people started on a heparin protocol, with no one paying attention to it, and a day later they still weren't therapuetic. It can happen, and there is a small chance it could be disatrous.

If you're giving the warfarin before the heparin is therapeutic, what's the reason of having a bridge? It's meaningless then because without a therapuetic aPTT, the heparin is not doing much.

Anyway, this is stupid now, I'm out.

I wonder why it takes days to reach therapeutic INR? Answer that and you'll understand why coumadin will not make you immediately hypercoagable.

 

[staup]

I wonder why it takes days to reach therapeutic INR? Answer that and you'll understand why coumadin will not make you immediately hypercoagable.

couldn't resist this one. nice try by the way.

read this to learn what actually happens: http://generalmedicine.suite101.com/article.cfm/warfarin

Look at the section on Mechanism of Action.

Patients definitely become hypercoagulable before they reach a therapeutic INR.

Not the best source but the first thing I found after doing a 5 sec google search.

 

[Hernandez]

couldn't resist this one. nice try by the way.

read this to learn what actually happens: http://generalmedicine.suite101.com/article.cfm/warfarin

Look at the section on Mechanism of Action.

Patients definitely become hypercoagulable before they reach a therapeutic INR.

Not the best source but the first thing I found after doing a 5 sec google search.

this rarely f clinical concern as long as you do as reccomended above and give the heparin/lmwh a few hours to become therapeutic. the concern is from my reading more theoretical. http://pubmedhh.nlm.nih.gov/cgi-bin/abstract.cgi?id=6548600&from=cqsrtbld

And several clinical trials have shown no adverse outcomes of signs of laboratory evidence of hypercoagulable issues with other assays http://www.ncbi.nlm.nih.gov/pubmed/12818245

and for non-urgent anticoagulation as long as you start at 4 or 5 mg coumarin you do no need Heparin bridge/overlap (page 14 of accp vit k anticoagulant guidelines)

 

[jdh71]

couldn't resist this one. nice try by the way.

read this to learn what actually happens: http://generalmedicine.suite101.com/article.cfm/warfarin

Look at the section on Mechanism of Action.

Patients definitely become hypercoagulable before they reach a therapeutic INR.

Not the best source but the first thing I found after doing a 5 sec google search.

I promise I understand the mechanism of action kid. I'm anticoagulating gomers all the time. Your link establishes why you bridge. Warfarin is an oral medication that takes days to establish it's anticoagulant effects by inhibiting vit K dependent co-factors in the liver. It also affects the the protein S and C pathways. However, unless you are protein C or S deficient you will have plenty of circulating protein C or S for the next 24-48 hours still in the blood stream. Warfarin does not immediately made you hypercoagulable. When starting heparin you give a bolus and run a wt based algorithm, following already established protocols, by the time the coumadin effect takes place on both 2, 7, 9, and 10, it will also have taken effect on protein C and S, and this is why you bridge.

Can you at least try for a tachnical source next time?

Or are you really done with the thread, and this time . . . you mean it!

 

[staup]

this rarely f clinical concern as long as you do as reccomended above and give the heparin/lmwh a few hours to become therapeutic. the concern is from my reading more theoretical.

Man, so mean. Anyway, I promise I'm out after this.

So as the quote referenced above states, and as almost every poster on this thread has agreed, you give warfarin once the heparin is therapeutic. You will almost always get away with giving it at the same time, but you technically should wait for the reasons I stated and referenced before until you know the patient is therapeutic, which is usually a couple of hours or maybe sooner with lmwh. I have seen it turn out badly when a patient started taking warfarin, was obese, and didn't become therapeutic on heparin for days.

So the study referenced above about procoagulant effects of warfarin is nice, but not terribly helpful because they used normal patients, not in a hypercoagulable state or with a clot, but only with afib, which we already knew is safe to do. The pathophysiology is quite different and not exactly relevant to that study. Certainly, the classic teaching is what I have referenced on this thread about the procoagulant effects.

Almost any source you look up will say start them on "the same day", not at "the same time", implying that reasonable people are waiting the several hours to make sure the patient is therapeutic or just chancing it.

So, if by saying "start them at the same time" jdh71, you implied on the same day, I can agree with that. If you meant you start them at exactly at the same time, I don't agree with that, and feel that most times it will work out, but you're chancing it a little.

Finally, the last line sentence Hernandez referenced about "non-urgent" anticoagulation means patient's that don't need to be anticoagulated right now, so a clot doesn't apply to that reasoning. That is more of an afib picture.

Sorry.